Study of AC drive type fluid-based resistive inclination sensor

In this research, one-axis high sensitive and low power consumption inclination sensor has been developed. The electric resistance of fluid between two electrodes is used to realize the sensor. A cap was attached to PCB board on which three electrodes were patterned. And propylene carbonate was encapsulated in it. Equivalent circuit model of the sensor was modeled using AC impedance method. DC and AC voltage were applied to a semicircle electrode, the other electrode was grounded and the voltage of an arc electrode was measured. The AC sensitivity was six times higher than the DC sensitivity at V_dd=5 V. The sensor can operate even at low AC voltage of IV. In addition, custom driving and detection circuit were developed and evaluated for practical application.